Method of producing filter rod sections or the like

ABSTRACT

Filter rod sections are produced by moving a tow of filamentary filter material past a device which showers the filaments with atomized plasticizer and by thereupon converting the thus treated tow into a rod-like filler which is wrapped to form a filter rod. The latter is severed to yield a succession of filter rod sections which are transported by a fluted drum to storage or to a machine for the production of filter-tipped smokers&#39;&#39; products. Groups of filter rod sections are withdrawn from the flutes of the drum at regular intervals for weighing to thus determine the quantity of filter material and/or plasticizer. The results of the weighing operation are utilized to adjust the feeding mechanism for the tow and/or plasticizer if the measured quantities deviate from desired quantities. The feeding mechanism for the tow employs rolls which can be driven at a variable speed to thereby subject the filaments of the tow to a more or less pronounced stretching action. The feeding mechanism for the plasticizer employs a rotary brush which removes plasticizer from the periphery of a drum dipping into a supply of plasticizer, and a variable-speed drive for the drum.

Greve [451 Feb. 11, 1975 METHOD OF PRODUCING FILTER ROD SECTIONS OR THELIKE Heinz Greve, Hamburg, Germany I-Iauni-Werke Korber & Co. KG,Hamburg, Germany Filed: May 15, 1973 Appl. No.: 360,598

Related US. Application Data Division of Ser. No. 131,167, April 5,1971, Pat. No. 3,741,846.

Inventor:

Assignee:

Foreign Application Priority Data Apr. 11, 1970 Germany 2017360 US. Cl.93/1 C, 93/77 FT, 131/261 A, 156/64, 156/360 Int. Cl. A24c 5/50 Field ofSearch 156/360, 64, 441; 131/261 A; 93/1 C, 77 FT References CitedUNITED STATES PATENTS 5/1967 Gallagher 156/441 X 1/1968 Watson 93/1 C UX2/1968 Davenport et a1. 93/1 C X 10/1968 Berger et a1. 93/1 C X FOREIGNPATENTS OR APPLICATIONS 1 1/1954 Great Britain 93/77 FT PrimaryExaminer-Granville Y. Custer, Jr. v Assistant E.raminer.lames F. CoanAttorney, Agent, or FirmMichael S. Striker [57] ABSTRACT Filter rodsections are produced by moving a tow of filamentary filter materialpast a device which showers the filaments with atomized plasticizer andby thereupon converting the thus treated tow into a rod-like fillerwhich is wrapped to form a filter rod. The latter is severed to yield asuccession of filter rod sections which are transported by a fluted drumto storage or to a machine for the production of filtertipped smokersproducts. Groups of filter rod sections are withdrawn from the flutes ofthe drum at regular intervals for weighing to thus determine thequantity of filter material and/or plasticizer. The results of theweighing operation are utilized to adjust the feeding mechanism for thetow and/or plasticizer if the measured quantities deviate from desiredquantities. The feeding mechanism for the tow employs rolls which can bedriven at a variable speed to thereby subject the filaments of the towto a more or less pronounced stretching action. The feeding mechanismfor the plasticizer employs a rotary brush which removes plasticizerfrom the periphery of a drum dipping into a supply of plasticizer, and avariable-speed drive for the drum.

1] Claims, 5 Drawing Figures PATENTEUFEBI 1 1975 saw 3 or 5CROSS-REFERENCE TO RELATED APPLICATION This is a division of mycopending application Ser. No. l3l,l67 filed Apr. 5, 1971, now Pat. No.3,741,846 granted June 26, 1973.

BACKGROUND OF THE INVENTION The present invention relates to a method ofproducing rod-shaped articles, particularly such rod-shaped articleswhich constitute or form part of smokers products including plain orfilter-tipped cigarettes, cigarillos and cigars. More particularly, theinvention relates to improvements in a method of producing rod-shapedarticles of the type wherein one or more main components are contactedby or otherwise treated or assembled with one or more secondarycomponents to form a rod-shaped intermediate product which is thereuponsubdivided into articles of desired length. Typical examples of sucharticles are filter rod sections wherein the main component consists ofa tow of filamentary filter material and the secondary or auxiliarycomponent is a plasticizer or bonding medium which is applied to the towin a liquid state and is thereupon caused or allowed to set in order toimpart to the filter rod sections a desirable resistance to deformationas well as to enhance the smoke-filtering characteristics of suchsections.

As a rule, the density of a tow of filamentary filter material whichconstitutes the main component of filter rod sections or filter elementsvaries within a wide range. Therefore, it is necessary to regulate thedensity of the tow prior to formation of a filler which is thereuponwrapped to form a rod and severed to yield filter rod sections ofdesired length. The filaments of the tow are crimped and the number ofcrimps per unit length of the two determines the density of therespective portions of the tow. In the absence of any regulating action,the density of filamentary filter material in filter rod sections wouldvary not only from increment to increment of a particular filter rodsection but also from section to section. Consequently, the resistancewhich the filter rod sections would offer to the passage of smoke wouldalso vary from filter cigarette to filter cigarette or fromfilter-tipped cigar to filter-tipped cigar. Such differences in theresistance of filter rod sections to the passage of smoke are highlyundesirable.

It is already known to provide a filter rod making machine with meansfor subjecting the tow to a variable stretching action for the purposeof reducing the difference between the densities of successiveincrements of the tow. East German Pat. No. 61,974 discloses a detectorwhich scans the tow and produces signals which are utilized forregulation of the stretching action. The detector is a pneumaticdetector which determines the resistance to the flow of an air streamacross successive increments of the tow or a beta ray detector whichincludes a source of beta rays at one side of the path of the tow and anionization chamber which is located opposite the source and furnishessignals indicating the rate at which the beta rays penetrate through thetow. A drawback of pneumatic detectors is that they are not alwaysreliable, i.e., a minor leak in a single one of several conduits whichconvey the air stream or streams is likely to cause the generation ofsignals which are not truly indicative of the density of measuredportions of the tow. Beta ray detectors are quite expensive and theymust be provided with-complicated safety devices to protect theattendants.

SUMMARY OF THE INVENTION An object'of the invention is to provide anovel and improved method of producing rod-shaped articles, particularlysections of filter rods wherein one or more main components areassembled with or contacted by one or more secondary components,according to which the quantity of one or more components in thearticles can be measured or determined in a novel and improved way andthe result of measurement used to insure that the quantity of suchcomponent or components does not appreciably deviate from a desiredquantity.

Another object of the invention is to provide a novel and improvedmethod of producing filter rod sections or filter elements for use inmachines for the production of filter cigarettes, cigars or cigarillos.

A further object of the invention is to provide a method of producingfilter rod sections or like rodshaped articles wherein not only theaverage quantity of one or more components per rod-shaped article butalso the quantity from increment to increment of any given article ismore uniform than in articles which are produced in accordance with thepresently known methods.

The method of the present invention is employed for the making of filterelements or analogous rod-shaped articles which constitute or form partof rod-shaped smokers products and are composed of at least one maincomponent (such as the aforementioned tow'of tilamentary filtermaterial) and at least one secondary or auxiliary component (such as theaforementioned plasticizer or bonding medium), especially a secondarycomponent which influences the condition of the main component (thus,the plasticizer softens portions of filaments and causes them to adhereto each other prior to setting). The method comprises the steps ofconverting effective quantities of the main and secondary componentsinto a rod, subdividing the rod into a succession of rod-shaped articlesof predetermined length, conveying the articles along a predeterminedpath, repeatedly removing selected articles or groups of selectedarticles from the path, measuring the quantity of at least one componentin the thus removed articles, and regulating the quantity of at leastone component in the course of the converting step in accordance withthe results of measurements.

If the main component is a tow of stretchable crimped filamentarymaterial and the regulating step includes regulating the quantity offilamentary material, the method further comprises the steps of storinga supply of filter material, continuously withdrawing from the supply atow of filter material, and subjecting the tow to a variable stretchingaction to thus determine the quantity of filter material in successiveincrements of the tow prior to the converting step. The regulating stepthen comprises changing the stretching action upon the filaments of thetow in accordance with the results of measurements.

The measuring step preferably comprises producing signals which areindicative of the measured quantity, and the regulating step comprisesutilizing the signals to change the stretching action when the signalsdeviate from a predetermined signal.

In accordance with an advantageous feature of the improved method, themeasuring step comprises weighing the removed selected rod-shapedarticles; such articles are preferably removed by means of one or morepneumatic ejectors which can be actuated at regular intervals or atdesired intervals to expel from the path for the rod-shaped articles adesired number of articles for weighing.

If the secondary component is a liquid which is applied in the form offinely dispersed droplets, the regulating means for the secondarycomponent may comprise a device which insures that the main componentreceives a predetermined quantity of secondary component per unit oftime.

In accordance with a more specific feature of the invention, the methodmay further comprise the steps of converting effective quantities of allbut one component into a second rod and subdividing the second rod intosecond rod-shaped articles of the same size and shape as the normallyproduced articles. The measuring step then comprises separately weighingequal numbers of normally produced second articles, comparing thecombined weight of the normally produced articles with the combinedweight of the second articles, and producing signals which areindicative of the difference between the two weights. The regulatingstep then comprises regulating the quantity of at least one component inthe first-mentioned converting step in accordance with the signals.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Themachine itself, however, both as to its construction and its mode ofoperation, will be best understood upon perusal of the followingdetailed description of certain specific embodiments with reference tothe accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic side elevationalview of a filter rod making machine which can be utilized for thepractice of my method;

FIG. 2 is an enlarged fragmentary view of a detail substantially as seenin the direction of arrow II in FIG. 1;

FIG. 3 is a diagram of the control circuit and of certain other parts inthe machine of FIG. 1;

FIG. 4 is a diagram of one of the two regulating units in the machine ofFIG. 1; and

FIG. 5 is a fragmentary detail view, similar to that of FIG. 2, of aportion of a modified filter rod making machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1,there is shown a filter rod making machine having a refillablereceptacle 1 containing a source 2 of a tow 5 of crimped filamentaryfilter material which is to be converted into the filler of a continuouswrapped filter rod 50. The source 2 of filamentary material in thereceptacle 1 is in the form of a bale and is drawn first upwardly andthereupon in a direction to the left by an adjustable feeding unit 9including a pair of variable-speed advancing rolls 11. On its way towardthe nip of the advancing rolls 11, the tow 5 passes along a nozzle 3having orifices facing a plate 4 and connected to a source of compressedair to direct air streams across the pathof the tow 5 in order to loosenor open the filaments and to impart to the tow the shape of a band whichis thereupon causedto pass around a deflecting roller 6. A second nozzle7 having orifices which face a plate 8 is installed between thedeflecting roller 6 and the advancing rolls 11 to further loosen or openthe filaments of the tow 5 before the tow undergoes a stretching ortensioning action in the zone between the advancing rolls 1] and asecond pair of advancing or tensioning rolls 12 which also form part ofthe adjustable feeding unit 9. The tensioning rolls 12 are normallydriven at a constant speed; however, the advancing rolls 11 are drivenat a'variable speed by a regulating unit 91 to thus determine thestretch of filaments which form the tow 5 and hence the quantity offilaments per unit'length of the tow.

The drive means for the tensioning rolls 12 comprises a variable-speedelectric motor 16 which drives a toothed pulley 13 on the shaft of thelower tensioning roll- 12 by way of an endless toothed belt 14 trainedover a toothed pulley l5-on the output shaft of the motor 16.

Theadvancing rolls 11 receive motion from the motor 16 by way of thebelt 14, a toothed pulley 17 on the shaft of the lower tensioning roll12, an endless toothed belt 18 which is trained over the pulley 17, anda toothed pulley 19 on the rotary input member of an infinitelyvariable-speed transmission 21 for the lower advancing roll 11. Thelatter is connected with the output member of the transmission 21 whichforms part of the aforementioned regulating unit 91. The ratio of thetransmission 21 can be changed by the output shaft 23 of an electricservomotor 22' which also constitutes an element of the regulating unit91.

The feeding unit 9 can change the quantity of the primary or maincomponent (filamentary filter material) in successive increments or unitlengths of the wrapped filter rod 50. A secondary or auxiliary componentof the filter rod is a liquid bonding medium or plasticizer 26 (e.g.,triacetin) which is stored in a vessel or tank 25 forming part ofasecond adjustable feeding or filamenttreating unit 24. The latterfurthercomprises two applicators 27, 28 the first of which is a rotary drumdipping into the supply of plasticizer 26 in the tank 25 to withdraw acontinuous film of plasticizer which is thereupon atomized by the secondapplicator 28, preferably a rotary brush which converts the film into aspray and directs the spray across the path for the opened or loosenedband-shaped tow 5 in a region downstream of the tensioning rolls 12.

The brush 28 is driven by a toothed pulley 32 by way of anelectromagnetic clutch 33 (see also FIG. 3). The pulley 32 is driven byan endless toothed belt 31 which is trained over a further toothedpulley 29 on the shaft for the lower tensioning roll 12. The drum 27 isdriven by a variable-speed d-c motor 30 through the intermediary of afirst toothed pulley 35 on the output shaft of the motor 30, a secondtoothed pulley 36 on the shaft of the drum 27, and an endless toothedbelt 37. The rate at which the feeding or treating unit 24 applies theplasticizer to the tow 5 is determined by a second regulating unit 34here shown as an electric or electronic circuit the details of which areillustrated in FIG. 4. The regulating unit 34 is of the type known asMINISEMI produced by the West-German Firm AEG. The feeding or treatingunit 24 occupies a station wherein the main or primary component (tow 5)is contacted by the secondary component (plasticizer 26) prior toconversion of the thus assembled components into the wrapped filter rod50. Such conversion begins after the properly treated tow 5 ,movesthrough and beyond the nip of two further advancing rolls 41 the lowerof which has a toothed pulley 44 driven by an endless toothed belt 43.The latter is trained over a toothed pulley 42 on the output shaft ofthe motor 16. Successive increments of the tow 5 which advance beyondthe rolls 41 are caused to pass through a condensing horn 38 whichconverts the tow into a rod-like filler ready to be provided with atubular wrapper during transport through a wrapping or rod-formingstation 39. This station accommodates a conventional wrapping device 40for a web 46 of paper or cork which is stored in the form of a bobbin 45and is being withdrawn by two advancing rolls 45a to travel along apaster 47 which coats at least one marginal portion or an entire surfaceof the web 46 with a film of adhesive before the thus coated web reachesthe upper stretch of an endless band 48 which is driven by the motor 16.The band 48 is trained over several guide rollers including thosenumbered 49, 51, 52 and 53. The latter is driven by the motor 16 by wayof a pair of toothed pulleys 54, 55 and an endless toothed belt 56.

The seam between the overlapping marginal portions of the wrapper whichis obtained in response to draping of the web 46 around the filler ofplasticized filaments (treated tow 5) is thereupon heated by aplate-like sealer 57 and the resulting wrapped filter rod 50 then movesinto the range of an orbiting knife (not shown) forming part of asevering device 58 of the type known as cutoff and normally employed forsevering of a wrapped cigarette or cigar rod in a cigarette rod or cigarrod making machine. The cutoff 58 severs the filter rod 50 at regularintervals to form a single file of filter rod sections or filterelements 60 of desired length (for example, six times unit length). Arotary accelerating cam 58a is mounted downstream of the cutoff 58 toaccelerate successive filter rod sections 60 and to propel them intosuccessive flutes 61 (see also FIG. 2) of an endless transportingconveyor here shown as a rotary drum 59 which is driven in synchronismwith the band 48 and with the knife of the cutoff 58 and serves toadvance the filter rod sections 60 along a predeter mined path, namely,sideways in the form of one or more rows and on toward a furtherconveyor (not shown) which can be employed to deliver the filter rodsections into the magazine of a filter cigarette or filter cigar makingmachine, not shown, into a tray filling machine, or directly intostorage.

The filter rod making machine further comprises a withdrawing unit 70for repeatedly withdrawing from the path defined by the transportingdrum 59 predetermined numbers of filter rod sections for measurement andfor generation of signals which are thereupon transmitted to theregulating units 34 and 91. Such signals are employed to change thequantity of the main component (filamentary filter material) andsecondary component (plasticizer 26) in the filter rod sections 60 whichare permitted to leave the machine for transport to storage or to afurther processing station. The withdrawing unit 70 cooperates with ameasuring or weighing unit 73 which determines the quantities ofcomponents in the withdrawn rod-shaped articles and is operativelyconnected with the regulating units 34 and 91 by way of a controlcircuit 89.

The withdrawing unit comprises two ejecting or segregating nozzles 62and 63 (see FIG. 2) which are adjacent to the path of rod-shapedarticles in the flutes 61 of the transporting drum 59. The nozzles 62,63 are connected with a source of compressed air (here shown as a blower69) through the intermediary of supply conduits 66, 67 whichrespectively contain normally closed electromagnetically operated valves64, 65 (see FIGS. 1 and 3). The solenoids for the valves 64, 65 arerespectively connected with adjustable counters 132, 134 shown in FIG.3. The connection between the pressure side of the blower 69 and thesupply conduits 66, 67 comprises a further supply conduit 68 shown inFIG. 1. The suction side of the blower 69 is connected with ports (notspecifically shown) which communicate with the flutes 61 of thetransporting drum 59 by way of a suction conduit 71 and a suitablyconfigurated groove (not specifically shown) in a stationary valve plate72 adjacent to one axial end of the drum 59. The arrangement is suchthat the transporting drum 59 normally retains by suction all suchfilter rod sections 60 which enter successive flutes 61 at the stationaccommodating the accelerating cam 58a and leave the respective flutes61 at a second transfer station where such filter rod sections areremoved from the drum 59 to be transported to storage or to a furtherprocessing station.

The aforementioned measuring or weighing unit 73 comprises twohigh-precision electronic weighing devices or scales 74 and 75 (see FIG.2) which respectively comprise article-receiving containers or trays 76, 77. An electronic weighing unit which can be used in the machine ofFIG. 1 is disclosed in Canadian Pat. No. 803,371. The trays 76, 77 flankan intercepting or collecting receptacle 84 and the distance between thecenter of each of the trays and the center of the receptacle 84 at leastapproximates the distance between the ejecting nozzles 62, 63. Thus,when the tray 76 is ready to receive rod-shaped articles which areexpelled from the flutes 61 by the air stream issuing from the nozzle62, the nozzle 63 is located at a level above the receptacle 84. On theother hand, when the receptacle 84 registers with the nozzle 62 (asshown in FIG. 2), the rodshaped articles which are being expelled fromthe flutes 61 by the air stream issuing from the nozzle 63 are caused todescend into the tray 77. The receptacle 84 and the trays 76, 77 aremounted on a carriage 78 which is reciprocable along a stationary guideor support 79 between the end position shown in FIG. 2 and another endposition in which the tray 76 registers with the nozzle 62.

The means for reciprocating the carriage 78 with reference to thesupport 79 comprises a reversible electric motor 81 whose output shaft82 constitutes a feed screw meshing with a spindle nut 83 fixed to orintegral with the adjacentend of the carriage 78. If desired, the feedscrew 82 can be driven by a transmission which receives torque from theoutput shaft of the motor 81.

The carriage 78 is provided with two actuating elements or trips 86, 85the former of which is mounted on the nut 83 and the latter of which ismounted at the opposite end of the carriage. The trips 85, 86respectively serve to actuate limit switches 87, 88 which are mountedadjacent to the path of the carriage 78 and are electrically connectedwith the solenoids for the ejecting valves 64 and 65.

As mentioned before, the regulating unit 91 for the adjustable feedingunit 9 includes the infinitely variable-speed transmission 21 and theelectric servomotor 22 whose output shaft 23 can be rotated clockwise orcounterclockwise to thereby change the transmission ratio and hence thespeed of the feeding or advancing rolls 11. The regulating unit 91further comprises a conventional electronic signal comparing circuit 92whose output is'connected with the servomotor 22 by way of an amplifier90 and which has two inputs one of which is connected with the controlcircuit 89 by way of conductor means 94. The other input of the signalcomparing circuit 92 is connected with a feeler or scanning device 93which scans the angular position of the output shaft 23 and producessignals which are indicative of the momentary ratio of the transmission21. The amplifier 90 is provided with conventional polarity reversingmeans, such as polarized relays, which can cause the servomotor 22 torotate its output shaft 23 in a counterclockwise direction or in aclockwise direction, depending upon whether the output signal from thesignal comparing circuit 92 indicates that the ratio of the transmission21 is to be changed in a direction to reduce-or in a direction toincrease the speed of the advancing or feeding rolls 11. The feeler 93may comprise a potentiometer whose wire is stationary and whose slideris connected with the output shaft 23 to select the resistance of thepotentiometer as a function of angular position of the shaft 23 andhence as a function of the momentary ratio of the transmission 21. Othertypes of feelers or scanning devices can be used with equal advantage.

The regulating unit 34 for the d-c motor 30 which drives the drum-shapedapplicator 27 and for the clutch 33 which transmits torque to thebrush-shaped applicator is shown in greater detail in FIG. 4. Asmentioned before, the illustrated regulating unit 34 is a socalledMlNlSEMl produced by the West-German Firm AEG and is a transistorizedcircuit including a tachometer generator 34a which serves to producesignals indicating the momentary speed of the motor 30 for theapplicator 27, a rectifier 34b, a semiconductive signal transmittingdevice 340, a pulse shaping device 34d, a transistor amplifier 34c, anda junction 34f for signals coming from the tachometer generator 34a andfrom a conductor means 97. The junction 34f transmits signals to theamplifier 34e. The conductor means 97 connects the junction 34] of theregulating unit 34 with the control circuit 89. A further conductormeans 95 connects the control circuit 89 with the clutch 33 for theapplicator 28 and with one input of the regulating unit '34. Theconductor means 95 is connected with the regulating unit 34 by way of arelay 96 having contacts 96a which can connect the elements 34b, 340 ofthe unit 34 with a source of polyphase current. The control circuit 89is further connected with the motor 16 by way of a cable 98 includingthe conductors 98a, 98b (see FIG. 3). Still further, the control circuit89 is connected with a control panel 101 by way of a three-conductorcable 99. The control panel 101 supports three speed changing devices inthe form of pushbuttons 102, 103, 104 which can be actuated by theperson in charge in order to change the speed of the motor 16. Thepushbutton 102 constitutes a starting device which can initiatecompletion of the circuit of the motor 16 and thereby causes the motor16 to be accelerated to the lower of two speeds. The pushbutton 103constitutes an accelerating device which is actuated (depressed) by aperson in charge in order to accelerate the motor 16 from the ton 104constitutes an arresting or decelerating device for the motor 16; thelatter is decelerated to zero speed within a certain interval of timewhen the pushbutton 104 is actuated while the motor 16 is driven at thenormal speed. A further pushbutton 105 on the control panel 101 isactuated when the operator wishes to withdraw samples of rod-shapedarticles 60 by way of the removing unit 70. l

The control circuit 89 is further connected with the measuring unit 73by way of conductor means 106, 107, 108. Additional conductor means 109,11! connect the control'circuit 89 with the solenoids of the valves 64,65 in the supply conduits 66, 67 for the ejecting or segregating nozzles62, 63 of the removing unit 70.

The details of the control circuit 89 are illustrated in FIGS. 2 and 3.That portion of the control circuit 89 which is connected with theelectromagnetic clutch 33 for the applicator 28 and with the regulatingunit 34 includes an amplifier 112, a signal storing circuitl13 and twologic circuits in the form of OR-gates 114, 115. That portion of thecontrol circuit 89 which is connected with the reversible motor 81 forthe carriage 78 of FIG. 3 includes a relay 116, an amplifier 117, asignal storing circuit 118-, an adjustable clockwork mechanism or timer119, the aforementioned limit switches 87, 88, a further relay 121, afurther amplifier 122, and a further signal storing circuit 123. Thatbranch or portion of the control circuit 89 which is connected with thesolenoid for the valve 64 includes an amplifier 124, an OR-gate 125, asignal storing circuit 126, additional OR-gates 127, 128, an adjustabletime-delay device 129, a further signal storing circuit 131, theaforementioned counter 132 and the pushbutton 105. The'control circuitbranch which is connected with the solenoid for the valve 65 includes anamplifier 133, the aforementioned counter 134, a signal storing circuit135 and an adjustable time-delay device 136. The counters 132, 134 canbe considered as constituting component-parts of the control circuit 89or of the removing unit 70; they are associated with a timer or pulsegenerator 137 of conventional design which is rotated in synchronismwith the transporting drum 59 and transmits to the counters 132 and 134signals at intervals which correspond to intervals between introductionof successive filter rod sections into the flutes 61 of the drum 59.

That portion or branch of the control circuit 89 which is connected withthe measuring unit 73 includes a differential circuit 138 (FIG. 2), asignal comparing junction 139 and a potentiometer 141 which isadjustable to furnish to the junction 139 a signal of preselectedmagnitude or intensity, a second adjustable potentiometer 143, and afurther junction 142 which is connected with the conductor means 94,with the conductor means 106 and with the potentiometer 143. Thejunction 139 is connected with the conductor means 97, with thepotentiometer 141 and with the output of the differential circuit 138.

That branch or portion of the control circuit 89 which is connected withthe speed changing devices 102, 103, 104 for the motor 16 comprises arelay 144, an amplifier 145, a signal storing circuit 146, an OR- gate147, a further relay 148, a further amplifier 149,

an adjustable time-delay device 151, a further signal storing circuit152, a further OR-gate 153 and a further adjustable time-delay device154. Each of the OR-gates (see, for example, the OR-gate 147 of FIG. 3)has two inputs a, b and an output c. The output transmits a signal aslong as at least one of the inputs a, b receives a signal. Each signalstoring circuit (see, for example, the circuit 146 of FIG. 3) has afirst input a which causes the output c to transmit a signal until theother input b receives an erasing signal. Thus, the output c of eachsignal storing circuit transmits a signal in response to momentary orcontinued reception of a signal at the input a and the transmission ofthe signal continues until the input b receives an erasing signal.

The Operation It is assumed that the filter rod making machine operatesnormally, i.e., that the motor 16 drives the belts 14, 43 and 56 at thehigher of two speeds. The feeding or advancing rolls 11 draw the tow .5at the normal speed and the applicators 27, 28 cooperate to apply anaverage quantity of atomized plasticizer 26 to each unit length of thetow. The carriage 78 dwells in the end position shown in FIG. 2 in whichthe nozzles 62, 63 respectively register with the receptacle 84 and tray77.

The timer 119 serves to trigger or initiate successive measuringoperations at preselected intervals. This timer can constitute aclockwork mechanism which completes a circuit whenever its pointer 119areaches the l2-oclock position to thus cause the transmission of asignal to the input a of the signal storing circuit 118. For example,the clockwork mechanism 119 may be adjusted in such a way that the inputa of the signal storing circuit 118 receives a signal every 30 minutes.The output 0 of the circuit 118 then transmits a signal to the amplifier117 which energizes the relay 116 so that the latter closes its contacts116a and connects one winding of the reversible motor 81 with a sourceof energy by way of power leads L. The motor 81 is started and begins tomove the carriage 78 along the support 79 in the direction indicated bythe arrow 155 shown in FIG. 2. The trip 85 actuates the limit switch 87when the carriage 78 reaches its second end position in which thenozzles 62, 63 respectively register with the tray 76 and receptacle 84.The limit switch 87 transmits a signal to the input b of the signalstoring circuit 118 whereby the circuit 118 ceases to energize the relay116 by way of the amplifier 117 so that the motor 81 comes to a halt.

The closing of the limit switch 87 by the trip 85 further results intransmission of a signal to the input a of the signal storing circuit131 whose output c transmits a signal to the amplifier 124 by way of thecorresponding input and the output of the OR-gate 125. The amplifier 124energizes the solenoid for the valve 64 which enables theconduit 66 toconvey to the nozzle 62 a stream of compressed air to expel filter rodsections 60 from successive flutes 61 of the transporting drum 59 and topropel such filter rod sections into the tray 76 of the scale 74. Eachexpelled filter rod section 60 is of the same quality or consistency asthe preceding nonexpelled filter rod sections, i.e., each expelledfilter rod section contains the same quantity of plasticizer 26 andfilamentary material as the preceding filter rod sections 60 which werepermitted to bypass the ejecting or removing station (nozzle 62). Thus,the expelled filter rod sections in the tray 76 are representative ofthe quality of filter rod sections which are being produced by themachine at the time when the clockwork mechanism 119 produces a signalor causes the generation of a signal for energization of the relay 116and for delayed energization of the solenoid for the valve 64 by meansof the limit switch 87. The number of filter rod sections 60 which areexpelled into the tray 76 depends on the setting of the counter 132which is started in response to the signal from the output 0 of thesignal storing circuit 131 simultaneously with opening of the valve 64,i.e., in response to closing of the limit switch 87. The counter 132counts the signals which are transmitted thereto by the timer 137; whenthe counter 132 receives n signals (n being the desired number of filterrod sections 60 which are to be expelled into the tray 76), it transmitsa signal to the erasing input b of the signal storing circuit 131whereby the latterterminates the transmission of a signal to theamplifier 124 (by way of the OR-gate so that the valve 64 closes andterminates the flow of compressed air to the nozzle 62. The counter 132is automatically reset to zero when it ceases to receive a signal fromthe output 0 of the signal storing circuit 131. l

The output signal from the counter 132 is further transmitted to theinput a of thesignal storing circuit 123 whose output c energizes therelay 121 by way of v the amplifier 122. The relay 121 closes itscontacts 121a to thus connect the power leads L with the other windingofthe motor 81 This motor begins to move the carriage 78 back to the endposition shown in FIG. 2 (see the arrow 156). The transmission of motionfrom the motor 81 to the carriage 78 takes place by way of the feedscrew 82 and nut 83. During movement of the carriage 78 back to the endposition shown in FIG. 2, the transporting drum 59 is free to deliverthe filter rod sections 60 (namely, those sections immediately followingthe sections which were caused to enter the tray 76 of the scale 74) totheir normal destination, e.g., into a tray filling machine, 'not shown.

When the carriage 78 reaches the end position of FIG. 2, the trip 86actuates (closes) the limit switch 88 which transmits a signal to theerasing input b of the signal storing circuit 123 whereby the latterdeenergizes the relay 121 and arrests the motor 81. At the same time,the signal which is generated in response to actuation of the limitswitch 88 reaches the erasing input b of the signal storing circuit 113by way of the OR-gate 115. The output c of the signal storing circuit113 ceases to transmit a signal to the amplifier 112 so that the clutch33 is deenergized to stop the applicator 28 and the relay 96 isdeenergized to open the circuit of the motor 30 for the applicator 27.Thus, the connection between the control circuit 89 and the regulatingunit 34 is interrupted. The feeding unit 24 for the plasticizer 26 isidle. It will be seen that the limit switch 88 constitutes a means fortemporarily arresting the feeding unit 24 to start the production offilter rod sections without plasticizer.

The signal which is generated in response to actuation of the limitswitch 88 is further transmitted to the input a of the signal storingcircuit 126 by way of the OR-gate 127. The output 0 of the circuit 126energizes the solenoid for the valve 64 by way of the amplifier 124 andOR-gate 125 so that the valve 64 permits the flow of compressed. air tothe nozzle 62. The signal which is generated in response to actuation ofthe limit switch 88 is also transmitted, with a delay determined by thedevice 136, to the input a of the signal storing circuit 135. Since thevalve 64 is open, the nozzle 62 expels into the receptacle 84 all suchfilter rod sections 1 1 which are produced and reach the transportingdrum 59 while the signal storing circuit 126 remains operative. Thesignal from the output of the signal storing circuit 135 not only causesopening of the valve 65 but also starts the counter 134. The counter 134receives pulses from the timer 137 and counts such pulses to transmit asignal to the erasing input b of the signal storing circuit 135 andtothus effect a closing of the valve 65 when the nozzle 63 completes theejection of a predetermined number of filter rod sections into the tray77 of the scale 75. It will be noted that the nozzle 63 is located aheadof the nozzle 62, as considered in the direction of rotation of thetransporting drum 59. The tray 77 receives filter rod sections which donot contain any plasticizer because such sections are producedsubsequent to deactivation of the feeding unit 24. The counter 134 isreset to zero when the emission of a signal at the output c of thesignal storing circuit 135 is terminated. The signal from the counter134 is further transmitted to the input a of the signal storing circuit113 by way of the OR-gate 114 whereby the amplifier 112 energizes theclutch 33 and the relay 96 which latter connects the motor 30 in theregulating unit 34 with the energy source. Thus, the applicators 27, 28of the feeding unit 24 are operative and begin to spray atomizedplasticizer 26 against successive increments of the tow 5. Theconstruction of the counter 134 is preferably identical with that of thecounter 132.

The output signal from the counter 134 is further transmitted to theinput b of the signal storing circuit 126 by way of the time-delaydevice 129 and OR-gate 128. Thus, the solenoid for the valve 64 isdeenergized by way of the OR-gate 125 and amplifier 124 so that thevalve 64 closes and disconnects the blower 69 from the nozzle 62.

The adjustment of the time-delay device 129 is such that the nozzle 62ceases to expel filter rod sections from the adjacent flutes 61 of thedrum 59 with a delay which is necessary in order to insure that thenozzle 62 expels all such filter rod sections which were produced whilethe feeding unit 24 was idle, i.e., all such filter rod sections whichdo not contain an effective quantity of plasticizer 26.

As shown in F168. 2 and 3, the output signal from the counter 134 isfurther transmitted to the scales 74, 75 by way of the conductor means108. The of 0s such signal to the two scales takes place at a time whenthe tray 76 already accommodates a predetermined number of filter rodsections which contain the main component (filaments) and the secondarycomponent (plasticizer 26) and when the tray 77 accommodates filter rodsections which contain the main component but not the plasticizer. Thenumber of filter rod sections in both trays is preferably the same. Thescales 7 4, 75 then produce voltage pulses which are transmitted to thecorresponding inputs of the differential circuit 138 by way of theconductor means 106, 107 (see FIG. 2). The intensity of pulses isrespectively indicative of the combined weight of filter rod sectionswith and without plasticizer 26. The circuit 138 computes the incomingpulses and transmits a signal which is indicative of the differencebetween the two pulses. Such signal reaches the junction 139 whichcompares the thus received sigv tensity of the signal from the output ofthe differential circuit 138. ln the case of a difference between theintensities of the two signals which are transmitted to the junction139, the latter transmits a signal to the junction 34fof the regulatingunit 34 by way of theconduc tor means 97. The regulating unit 34 thenselects a different speed for the motor 30to thus insure that the rateat which the feeding unit 24 furnishes atomized plasticizer 26 tosuccessive increments of the tow 5 is a function of the intensity of thesignal furnished by the potentiometer 141. The adjusted speed of themotor 30 remains unchanged during the interval between two successivesignals from the clockwork mechanism 119. The changes in speed of themotor 30 immediately result in a change of the rate of application ofatomized plasticizer 26 because the applicator 27 withdraws more or lessplasticizer from the supply in the tank 25, depending on an increase ora reduction in the speed of the motor 30. The acceleration ordeceleration of the motor 30 depends on the sign of the signal which isfurnished by the junction 139 to the junction 34f of the regulating unit34.

The signal from the scale is indicative of the combined weight of filterrod sections (without plasticizer 26) in the tray 77 and is transmittedby the conductor means 106 to the corresponding input of thedifferential circuit 138 as well as to one input of the signal comparingjunction 142. The latter receives from the po tentiometer 143 a signalwhich is indicative of the .desired weight of filter rod sectionswithout plasticizer (i.e., of the quantity of main component in eachfilter rod section). In the case of a difference between the intensitiesof signals which reach the junction 142, the latter transmits a signalto the corresponding input of the signal comparing circuit 92 in theregulating unit 91' (by way of the conductor means 94), and the thustransmitted signal causes appropriate modification of the signal to theamplifier which causes the motor 22 to'bring about an appropriate changein the ratio of the transmission 21 for the advancing or feeding rolls11. Thus, the speed at which the rolls 11 draw the tow 5 from thereceptacle 1 is changed in dependency on the nature of the signal fromthe junction 142 so that the tension of the tow in the zone between therolls l1 and 12 changes with the result that the quantity of filtermaterial per unit length of the tow conforms to the quantity indicatedby the signal from the potentiometer 143. The thus selected speed atwhich the advancing rolls 11 draw the tow 5 from the receptacle 1remains unchanged during the interval between two successive signalsfrom the clockwork mechanism 119;. The adjustment of the ratio oftransmission 21 is terminated when the feeler 93 transmits to thecorresponding input of the circuit 92 a signal which indicates that themomentary ratio equals the desired ratio (signal from the junction 142).The motor 22 can rotate its output shaft 23 in either direction,depending on the (positive or negative) sign of the signal from thejunction 142. if the weight of filter rod sections in the tray 77exceeds a weight which is indicated by the signal from the potentiometer143, the regulating unit 91 reduces the speed of the advancing rolls 11so that the tow 5 is subjected to a more intensive stretching action andthereupon contains a reduced quantity of filaments per unit length.inversely, the regulating unit 91 increases the speed of the advancingrolls 11 and thus reduces the stretch upon filaments if the signal fromthe scale 75 indicates that the combined weight of filter rod sections(without plasticizer) in the tray 77 is less than indicated by thesignal from the potentiometer 143. The signal at the output of thecircuit 92 disappears when the ratio of the transmission 21 is afunction of the signal from the potentiometer 143, and the motor 22 isthen arrested. It will be seen that the change in tensioning of the towin the zone between the rolls 11 and 12 is a function of the differencebetween a signal from the scale 75 which indicates the weight of apredetermined number of filter rod sections without plasticizer and thesignal from the potentiometer 143. Analogously, the change in the rateof application of the plasticizer 26 is a function of the differencebetween the signal from the scale 74 and the signal from thepotentiometer 141. Consequently, the average quantity of filter materialand plasticizer in each filter rod section which is permitted to leavethe machine by the normal route is within a desired range becauseperiodic adjustments by the regulating units 91 'and 34 insure thatdeviations from the desired weight cannot last longer than the length ofan interval between successive signals from the clockwork mechanism 119.The quantities of filter material and plasticizer are selected with aview to insure that the density and firmness of each finished filter rodsection 60 are best suited for appropriate filtering of smoke when thefilter rod sections are united with sections of wrapped tobacco rods ina machine for the production of filter-tipped cigarettes, cigars orcigarils.

As mentioned before, the removing or withdrawing unit 70 automaticallysegregates or expels those filter rod sections which are produced whilethe speed of the motor 16 is being changed from zero speed to a lowerspeed, from a lower speed to a higher speed, and from a higher or lowerspeed to zero speed. This is achieved as follows.

When the operator actuates the starting pushbutton 102 while the motor16 is idle, the signal which is generated in response to actuation ofthe pushbutton 102 is transmitted to the input a of the signal storingcircuit 146 to cause energization ofthe relay 144 by way of theamplifier 145. The relay 144 moves its contacts 144a to closed positionsto thereby connect a first winding of the motor 16 with the energysource by way of power leads L. The motor 16 is accelerated to the lowerof two speeds within a certain interval of time. Even though the motor16 is running, the feeding unit 24 is inactive because the clutch 33 andthe relay 96 are deenergized so that the applicators 27 and 28 are at astandstill.

The signal which is generated in response to actuation of the startingpushbutton 102 is further transmitted to the input a of the signalstoring circuit 126 by way of the OR-gate 127. Therefore, the circuit126 causes energization of the solenoid for the valve 64 by way of theOR-gate 125 and amplifier 124. The nozzle 62 receives compressed air andexpels successive'filter rod sections (which are without plasticizerbecause the feeding unit 24 is idle) into the receptacle 84. Theejection of filter rod sections into the receptacle 84 is continued aslong as the motor 16 is operated at the lower of two speeds. This isobviously desirable since the filter rod sections which are producedduring such stage of operation are without plasticizer.

When the operator thereupon decides to actuate the acceleratingpushbutton 103, the input b of the signal storing circuit 146 receives asignal by way of the OR- gate 147 whereby the circuit 146 deenergizesthe relay 144 to disconnect the first winding of the motor 16 from theenergy source. At the same time, the signal which is-generated onactuation of the pushbutton 103 reaches the input a of the signalstoring circuit 152 whose output 0 transmits a signal to the amplifier149 to energize the relay 148 which closes its contacts 148a and thusconnects the energy source (leads L) with the second winding of themotor 16. The latter is thereby accelerated from the lower to the higheror normal speed. Such acceleration takes up a certain interval of time.

The input a of the signal storing circuit 152 receives a signalsimultaneously with the input a of the signal storing circuit 113.Therefore, the amplifier 112 energizes the clutch 33 and the relay 96 tocouple the rotating pulley 32 to the applicator 28 and to connect themotor with the energy source whereby the applicators 27, 28 begin tospray atomized plasticizer 26 against successive increments of the tow 5while such increments pass through the feeding unit 24. The input a ofthe signal storing circuit 113 receives the signal from the pushbutton103 by way of the OR-gate 114. The connection of the second winding ofthe motor 16 with the energy source takes place simultaneously withdeenergization of the relay 144 so that the motor 16 is accelerated,without any delay, from the lower speed to the higher speed which isneeded to insure that each increment of the tow 5 receives an optimumpercentage of plasticizer. Thus, successive increments of the tow 5 arenot expected to receive an optimum quantity of plasticizer during theinterval which elapses between energization of the relay 148 and thecompleted acceleration of motor 16 to the higher speed. Therefore, it isdesirable to continue with the ejection of filter rod sections until thefilter rod sections which reach the nozzle 62 invariably contain optimumquantities of plasticizer.

The solenoid for the valve 64 (nozzle 62) is deenergized in response toa signal from the output 0 of the signal storing circuit 152 but with adelay which is determined by the time-delay device 151 which transmitsthe delayed signal to the erasing input b of the signal storing device126 by way of the OR-gate 128. Thus, the valve 64 closes and the filterrod sections 60 can travel past the nozzle 62 without being expelledinto the receptacle 84. The machine then continues to turn outsatisfactory filter rod sections 60 as long as the energy source remainsconnected with the second winding of the motor 16 (relay 148) and withthe motor 30 for the applicator 27. Thus, the feeding unit 24 isoperative and each increment of the tow 5 (which is subjected to arequisite stretching action during travel in the zone between the rolls11 and 12) is provided'with a predetermined quantity of plasticizer 26.As mentioned above, the closing of valve 64 takes place with a delaywhich is determined by the time-delay device 151 and is preferablyselected in such a way that the valve 64 closes subsequent toacceleration of the motor 16 to normal speed and by further insuringthat all filter rod sections which do not as yet contain the desiredquantity of plasticizer are expelled into the receptacle 84.

If the operator actuates the arresting pushbutton 104 while the motor 16is operated at the lower speed (in response to actuation of thepushbutton 102), the OR- gate 147 transmits a signal to the erasinginput b of the signal storing circuit 146 so that the latter deenergizesthe relay 144 and causes immediate stoppage of the motor 16.

If the arresting pushbutton 104 is actuated while the motor 16 isoperated at the normal or higher speed, the OR-gate 115 transmits asignal to the erasing input b of the signal storing circuit 113 whichdeenergizes the clutch 33 and the relay 96 by way of the output andamplifier 112 to immediately arrest the applicators 27 and 28. At thesame time, the OR-gate 127 immediately transmits a signal to the input aof the signal storing circuit 126 which energizes the solenoid for thevalve 64 so that the nozzle 62 begins to expel filter rod sections intothe receptacle 84. The signal from the pushbutton 104 is furthertransmitted to the erasing input b of the signal storing circuit 152 byway of the OR-gate 153 with a delay which is determined by thetime-delay device 154. Therefore, the signal at the output 0 of thesignal storing circuit 152 disappears to deenergize the relay 148 withsuch a delay that the nozzle 62 invariably expels into the receptacle 84all filter rod sections which are produced subsequent to deactivation ofthe feeding unit 24. Thus, the machine does not contain any suchportions of the tow S which are treated with plasticizer 26 when themotor 16 is idle. This eliminates problems during starting of the motor16 when the production is resumed.

It will be seen that the machine is arrested immediately if thepushbutton 104 is actuated while the motor 16 is running at the lowerspeed. This is due to the fact that the feeding unit 24 is then idle sothat the tow which remains in the machine when the motor 16 is idle doesnot contain any plasticizer. On the other hand, when the pushbutton 104is actuated while the motor 16 is running at full speed, stoppage of themotor 16 (deenergization of the relay 148 and opening of contacts 148a)takes place with a delay (device 154) which is long enough to insurethat the nozzle 62 expels all filter rod sections which might contain atleast some plasticizer. Therefore, the tow which remains in the machinewhile the motor 16 is idle. is always free of plasticizer to thus insurethat the machine can be started without any difficulties which normallyarise if the starting takes place while the wrapping mechanism and/orotherparts of the machine contain portions of tow which are impregnatedwith hardened plasticizer. The feeding unit 24 is deactivated inimmediate response to actuation of the pushbutton 104 while the motor 16is running at normal speed. The feeding unit 24 is not active when themotor 16 is running at the lower speed; therefore, the motor 16 can bearrested in immediate response to actuation of the pushbutton 104.

If an operator wishes to withdraw samples of filter rod sections 60 at atime other than that determined by the clockwork mechanism 119, forexample, to examine the appearance of filter rod sections, the operatoractuates the pushbutton 105 to transmit a signal to the amplifier 124directly through the OR-gate 125 so that the amplifier 124 energizes thesolenoid for the valve 64 which opens and enables the nozzle 62 to expelsuccessive filter rod sections 60 from the flutes 61 of the transportingdrum 59 into the receptacle 84. The ejection of sections 60 into thereceptacle 84 continues as long as the operator maintains the pushbutton105 in depressed position. Thus, the machine permits withdrawal of anydesired number of samples at any desired time, merely by depressing thepushbutton 105 while the motor 16 continues to run at the normal speed.

The provision of a regulating unit 91 for the feeding unit 9 whichcontrols the quantity of filamentary filter material per unit length ofthe tow 5 is particularly important because the filamentary materialconstitutes the main component of each filter rod section 60. Reliableoperation of the regulating unit 91 is also importantbecause the weightof successive increments of the tow 5 is much more likely to fluctuatewithin a very wide range than the quantity of plasticizer per unitlength of the tow since the filaments are crimped and the number ofcrimps is likely to vary from filament to filament as well as betweensuccessive lengths of a single filament. However, the accuracy ofregulating action upon the feeding unit 9 cannot be increased beyond acertain limit, mainly due to technological reasons as well as due toinertia of moving parts and limits in the accuracy of finish of machineparts. Therefore, it is desirable to provide the machine with discreteregulating means for each component of the filter rod or at least forthe two most important components (filter material and plasticizer). Thequantity of plasticizer per unit length of the tow 5 is likely tofluctuate for a number of, reasons. For example, if the opening orspreadingaction of nozzles 3 and 7 is not uniform, the tow 5 is likelyto reach the feeding unit 24 in the form of a band whose width variesfrom increment to increment and, therefore, the band will interceptdifferent quantities of atomized plasticizer during travel past theapplicators 27 and 28. The differences in width of the opened tow duringtransport through the feeding unit 24 are likely to influence the weightof'the filter rod sections 60. The quantity of applied plasticizer isalso likely to fluctuate due to temperature changes which influence theviscosity of the supply in the tank 25. Furthermore, the atomizingaction of the application or 28 is affected by wear on its bristles.Thus, there are many reasons to warrant a measurement of the quantity ofplasticizer in the filter rod sections 60 which are about to leave themachine and to regulate the feeding unit 24 in accordance with signalswhich are being transmitted to the regulating unit 34.

The weighing unit is but one of several measuring units which can beutilized in the machine of the present invention. As a matter' of fact,certain other types of measuring means (such as devices which employ,beta raysand ionization chambers) exhibit the advantage that they cancontinuously measure the quantity of one or more components insuccessive increments of the rod 50 so that the removing or withdrawingmeans 73 can be dispensed with. The same holds true for aforementionedpneumatic measuring or detecting devices which determine the resistanceoffered by successive increments of the tow to the passage of an airstream. It is further possible to employ a pair of electrodes which areconnected with a source of highfrequency current and are placed at theopposite sides of the path for the filter rod 50 or filter rod sections60. Nevertheless, one or more precision weighing devices are preferredat this time because they are capable of determining the quantities ofone or more components with an extremely high degree of accuracy,especially if the articles are not weighed singly but in groups each ofwhich consists of a substantial number of articles. Removal of groups atpredetermined intervals in response to signals from the clockworkmechanism or timer 119 is advantageous because the samples can bewithdrawn automatically without necessitating any attention on the partof the operators.

As described above, the machine of FIGS. 1 to 4 is provided with tworegulating units 91 and 34 which respectively adjust the feeding unit 9for the tow (main component) and the feeding unit 24 (source of thesecondary component 26). However, it is equally within the purview ofthe invention to modify the machine of FIGS. 1 to 4 in such a way thatthe regulating unit 91 is either omitted or rendered inactive so thatthe advancing rolls 11 are driven at a constant speed and the regulatingunit 34 adjusts the rate of application of the plasticizer 26 inresponse to signals by way of the conductor means 97. In addition toomission or deactivation of the regulating unit 91, the thus simplifiedmachine can operate properly by omitting the junction 142, thepotentiometer 143 and the conductor means 94. Also, the transmission 21can be replaced with a simpler transmission. In all other respects, theoperation of the thus modified machine is clearly analogous to operationof the machine shown in FIGS. 1 to 4.

If it is desired to use a feeding unit which is designed to furnish aconstant quantity of plasticizer 26 per unit of time, i.e., to operatethe machine with the regulating unit 91 but without the regulating unit34, the regulating unit 34 can be deactivated or omitted together withthe scale 74, and the other scale can be fixedly mounted to receivefilter rod sections in response to operation of the withdrawing orremoving unit. A portion of such modified machine is shown in FIG. 5.All such parts of the structure shown in FIG. 5 which are identical withor clearly analogous to the corresponding parts of the machine shown inFIGS. 1 to 4 are denoted by similar reference characters plus 200.

The withdrawing or removing unit of FIG. 5 comprises a single ejectornozzle 262 which is connected with a source of compressed air by way ofa supply conduit 266 and is adjacent to the path of filter rod sections260 which travel in the flutes 261 of the transporting drum 259. Thevalve 264 in the supply conduit 266 is normally closed and its solenoidis energized in response to a signal from the timer or clockworkmechanism 319 by way of the signal storing circuit 326 and amplifier324. The clockwork mechanism 319 is connected with the input a and theamplifier 324 is connected with the output 0 of the circuit 326. Theoutput c is further connected with an adjustable pulse counter 332 whichreceives pulses from a timer 337 at a frequency which is proportional tothe rate of travel of flutes 261 past the nozzle 262. The output of thecounter 332 is connected with the erasing input b of the signal storingcircuit 326 and with the scale 274 which is stationary and whose tray276 is positioned to intercept filter rod sections which are expelled bythe air stream issuing from the nozzle 262. The scale 274 transmitssignals to a junction 342 which is connected with the regulating unit 91(not shown) by way of a conductor means 294 and with a potentiometer 343which corresponds to the potentiometer 143 of FIG. 2.

The clockwork mechanism 319 is set to transmit to the input a of thesignal storing circuit 326 signals at predetermined intervals, forexample, every hour or every thirty minutes. The output c of the circuit326 then transmits a signal which energizes the solenoid for the valve264 by way of the amplifier 324 and which also starts the properlyadjusted pulse counter 332. The

latter counts the pulses which are transmitted by the timer 337 at therate at which the nozzle 262 expels filter rod sections 260 from theflutes 261 of the drum 259 into the tray 276. When the counter 332receives a preselected number of pulses, i.e., when the tray 276accumulates a predetermined number of filter rod sections 260, theoutput of the counter 332 transmits a signal to the input b of thesignal storing circuit 326 to erase the signal at the output 0 and tothus deenergize the solenoid for the valve 264 with resultingdeactivation of the withdrawing unit. At the same time, the counter 332transmits a signal to the scale 274 which determines the combined weightof filter rod sections 260 in the tray 276 and transmits an appropriatesignal to the junction 342. The latter compares such signal with thesignal from the potentiometer 343 (i.e., with a signal which isindicative of the desired weight of filter rod sections 260 in the tray276), and the conductor means 294 transmits (if necessary) a signal tothe regulating unit 91 so that the unit 91 adjusts the stretch ofsuccessive portions of the tow 5 between the advancing rolls 1! and 12.The scale 274 can complete the weighing operation prior to or inresponse to reception of a signal from the counter 332.

An important advantage of the improved method is that the quality andconsistency of filter rod sections which reach a processing machine(e.g., a filter cigarette making machine) is much more uniform than inpresently known filter rod making machines and also that the number ofrejects is reduced considerably because any adjustments which mightbecome necessary are carried out without requiring any attention on thepart of the operators. The consistency of a satisfactory filter rodsection is preferably uniform all the way from the one end to the otherend, and this can be readily achieved by automatically regulating thequantity of at least one component of each filter rod section and byinsuring the expulsion or segregation of all such filter rod sectionswhich are produced during those stages of operation when the machine islikely to turn out unsatisfactory products. Another important advantageof the improved method is that it can be rapidly converted from theproduction of a first type of rod-shaped articles to the production ofany one of several other types of articles merely by changing theplasticizer in the tank 25, by replacing the bale 2 with a baleconsisting of or containing another material, by adjusting thepotentiometer 141, and/or by adjusting the potentiometer 143 (343). Anadvantage of the aforedescribed measuring, feeding, regulating andremoving units is that they can be built into or combined with existingtypes of filter rod making machines or other machines wherein two ormore components are to be assembled or brought in contact with eachother in accurately metered quantities. Since the articles to be weighedare removed directly from the path wherein the articles normally traveltoward the outlet of the machine, the weighed articles are trulyrepresentative of the quality of the output of the machine.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of my contribution to the art and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. A method of making filter elements or analogous rod-shaped articleswhich are composed of at least one main component and at least onesecondary component, particularly a secondary component which influencesthe condition of the main component, comprising the steps of convertingeffective quantities of main and secondary components into a rod;subdividing the rod into a succession of rod-shaped articles wherein thequantity of the main component is measurable independently of thequantity of the secondary component and vice versa; conveying therod-shaped articles along a predetermined path; carrying out repeatedmeasurements of the quantity of at least one component in selectedrod-shaped articles; and regulating the quantity of at least onecomponent in said converting step in accordance with the results of saidmeasurements.

2. A method as defined in claim 1, wherein said regulating stepcomprises regulating the quantity of said secondary component.

3. A method as defined in claim 2, wherein said main component is a towof filamentary filter material and said secondary component is appliedto the surface of filaments which form said tow.

4. A method as defined in claim 1, further comprising the step ofrepeatedly removing selected articles from said path, said measuringstep comprising weighing the thus removed rod-shaped articles.

5. A method as defined in claim 4, wherein said regulating stepcomprises adding in the course of said converting step a predeterminedquantity of at least one component per unit of time.

6. A method as defined in claim 4, wherein said removing step comprisesautomatically expelling from said path predetermined numbers ofrod-shaped articles.

7. A method as defined in claim 1, wherein said measuring step comprisesweighing predetermined numbers of rod-shaped articles, comparing thethus obtained weight with a predetermined weight, and producing signalswhich are indicative of the difference between said weights, saidregulating step comprising adjusting in said converting step thequantity of at least one component in dependency on said signals.

8. A method as defined in claim 1, wherein said measuring step isrepeated at predetermined intervals.

9. A method of making rod-shaped filter elements which are composed ofat least one main component of stretchable filamentary filter materialand at least one secondary component, particularly a secondary componentwhich influences the condition of the main component, comprising thesteps of storing a supply of crimped filter material; continuouslywithdrawing a tow of filter material from said supply; subjecting thetow to a variable stretching action to thus regulate the crimp and tothereby determine the quantity of filter material in successiveincrements of the tow; converting effective quantities of stretched towand secondary component into a rod; subdividing the rod into asuccession of rod-shaped filter elements; conveying the filter elementsalong a predetermined path; carrying out repeated measurements of thequantity of at least one component in selected filter elements; andregulating the quantity of filter material in said converting step,including changing said stretching action in accordance with the resultsof said measurements.

10. A method as defined in claim 9, wherein said measuring stepcomprises producing signals which are indicative of the measuredquantity and said regulating step comprises utilizing said signals tochange sad stretching action when the signals deviate from apredetermined signal.

11. A method of making filter elements or analogous rod-shaped articleswhich are composed of at least one main component and at least onesecondary component, particularly a secondary component which influencesthe condition of the main component, comprising the steps of convertingeffective quantities of main and secondary componentsinto a first rod;subdividing the first rod into a succession of first rod-shapedarticles; conveying the first rod-shaped articles along a predeterminedpath; converting effective quantities of all but one of said componentsinto a second rod and subdividing the second rod into second rod-shapedarticles of the same size and shape as the first articles; repeatedlymeasuring the quantity of at least one component in selected firstarticles, including separately weighing equal numbers of first andsecond articles, comparing the combined weight of first articles withthe combined weight of second articles, and producing signals which areindicative of the difference between said weights; and regulating thequantity of at least one component in said first mentioned convertingstep in accordance with the results of said measurements, includingregulating the quantity of at least one component in said firstmentioned converting step in accordance with said

1. A method of making filter elements or analogous rod-shaped articleswhich are composed of at least one main component and at least onesecondary component, particularly a secondary component which influencesthe condition of the main component, comprising the steps of convertingeffective quantities of main and secondary components into a rod;subdividing the rod into a succession of rod-shaped articles wherein thequantity of the main component is measurable independently of thequantity of the secondary component and vice versa; conveying therod-shaped articles along a predetermined path; carrying out repeatedmeasurements of the quantity of at least one component in selectedrod-shaped articles; and regulating the quantity of at least onecomponent in said converting step in accordance with the results of saidmeasurements.
 2. A method as defined in claim 1, wherein said regulatingstep comprises regulating the quantity of said secondary component.
 3. Amethod as defined in claim 2, wherein said main component is a tow offilamentary filter material and said secondary component is applied tothe surface of filaments which form said tow.
 4. A method as defined inclaim 1, further comprising the step of repeatedly removing selectedarticles from said path, said measuring step comprising weighing thethus removed rod-shaped articles.
 5. A method as defined in claim 4,wherein said regulating step comprises adding in the course of saidconverting step a predetermined quantity of at least one component perunit of time.
 6. A method as defined in claim 4, wherein said removingstep comprises automatically expelling from said path predeterminednumbers of rod-shaped articles.
 7. A method as defined in claim 1,wherein said measuring step comprises weighing predetermined numbers ofrod-shaped articles, comparing the thus obtained weight with apredetermined weight, and producing signals which are indicative of thedifference between said weights, said regulating step comprisingadjusting in said converting step the quantity of at least one componentin dependency on said signals.
 8. A method as defined in claim 1,wherein said measuring step is repeated at predeterminEd intervals.
 9. Amethod of making rod-shaped filter elements which are composed of atleast one main component of stretchable filamentary filter material andat least one secondary component, particularly a secondary componentwhich influences the condition of the main component, comprising thesteps of storing a supply of crimped filter material; continuouslywithdrawing a tow of filter material from said supply; subjecting thetow to a variable stretching action to thus regulate the crimp and tothereby determine the quantity of filter material in successiveincrements of the tow; converting effective quantities of stretched towand secondary component into a rod; subdividing the rod into asuccession of rod-shaped filter elements; conveying the filter elementsalong a predetermined path; carrying out repeated measurements of thequantity of at least one component in selected filter elements; andregulating the quantity of filter material in said converting step,including changing said stretching action in accordance with the resultsof said measurements.
 10. A method as defined in claim 9, wherein saidmeasuring step comprises producing signals which are indicative of themeasured quantity and said regulating step comprises utilizing saidsignals to change sad stretching action when the signals deviate from apredetermined signal.
 11. A method of making filter elements oranalogous rod-shaped articles which are composed of at least one maincomponent and at least one secondary component, particularly a secondarycomponent which influences the condition of the main component,comprising the steps of converting effective quantities of main andsecondary components into a first rod; subdividing the first rod into asuccession of first rod-shaped articles; conveying the first rod-shapedarticles along a predetermined path; converting effective quantities ofall but one of said components into a second rod and subdividing thesecond rod into second rod-shaped articles of the same size and shape asthe first articles; repeatedly measuring the quantity of at least onecomponent in selected first articles, including separately weighingequal numbers of first and second articles, comparing the combinedweight of first articles with the combined weight of second articles,and producing signals which are indicative of the difference betweensaid weights; and regulating the quantity of at least one component insaid first mentioned converting step in accordance with the results ofsaid measurements, including regulating the quantity of at least onecomponent in said first mentioned converting step in accordance withsaid signals.